Scientists have achieved a significant milestone by mapping the shape of a supernova, a feat never accomplished before. The supernova, designated SN 2024ggi, erupted approximately 22 million light-years away in the galaxy NGC 3621, located in the constellation Hydra. This groundbreaking observation was made possible through rapid responses from astronomers following the initial detection on April 10, 2024, by the Asteroid Terrestrial-impact Last Alert System (ATLAS).
Just 26 hours after the initial detection, researchers utilized the Very Large Telescope (VLT) in Chile to examine the supernova during its early phase. This time-sensitive opportunity allowed scientists to observe the initial moments of the star’s explosive demise, which are typically lost if observations are delayed even by a day. The VLT’s data has provided a remarkable artist’s interpretation of the explosion, highlighting its distinctive shape.
Understanding the mechanics of supernova explosions is crucial, as it reveals the lifecycle of massive stars. A massive star, with a mass approximately 12 to 15 times that of the sun, maintains its spherical shape through a careful balance between gravitational forces and the outward pressure generated by nuclear fusion. Once this balance is disrupted, the star collapses under its own gravity, leading to an explosive release of energy.
This collapse creates a powerful shock wave that rips the star apart. The initial phase of this shock wave is crucial for understanding how the explosion expands and interacts with surrounding materials. Traditionally, the formation and propagation of this shock wave have been subjects of debate within the astronomical community.
First Observations Reveal Unique Structure
The VLT used a specialized technique known as spectropolarimetry to analyze the light emitted from the supernova. This method sorts light by its wavelengths and measures the direction of light wave vibrations. The findings revealed that the first light from the explosion was not emitted uniformly. Instead, it indicated that the shock wave had taken on an elongated shape, akin to an olive, rather than a perfect sphere.
As the supernova’s blast progressed, the light emitted began to interact with the surrounding gas, providing further insights. By around day ten post-explosion, the outer hydrogen-rich layers of the star became visible. Notably, these layers aligned with the same axis as the original shock wave, suggesting that the explosion maintained a directional shape from its outset. This consistent orientation hints at an underlying mechanism that governs the dynamics of such explosions.
The analysis of SN 2024ggi has yielded critical insights, ruling out some existing supernova models while lending support to others. This study contributes to a deeper understanding of the catastrophic processes underlying the deaths of massive stars. The research findings were published on November 12, 2025, in the journal Science Advances.
The implications of this discovery extend beyond academic interest, as they enhance our understanding of stellar evolution and the life cycles of galaxies. Such insights may ultimately inform our comprehension of cosmic phenomena and the fundamental forces that shape our universe.
